Looking for any advice on how people have found the relative data speeds on T Mobile & Three 3G networks.

Thought I was all sorted to order my iPhone5 today, switching carrier from orange to T Mobile to use the Full Monty plan. My thinking was this: Orange+TMobile shared network = better coverage than Three, plus unlimited data, plus opportunity to switch to EE's 4G plans with ease should they come to my area inside of 24mnth contract.

then I made the mistake of reading forums talking about how poor Orange/T Mobiles data speeds are. So I started flip flopping back to the idea of the One Plan, until I read Three can throttle speeds to suit their needs too.

I guess my question is, are they all much of a muchness, or for data, is there a big difference between T Mobile & three that anyone knows of?

I'm not a massive data power user, but I do want freedom to stream some content without worrying about limits.

I know it makes me a Billy No Mates replying to my own post, but never the less, just read that EE are claiming they're upgrading 3G services on Orange & T Mobile as part of the overhaul, so this could theoretically make T Mobile a good bet with improved 3G speeds and an already good network coverage.